When an article such as a precision machine that is apt to damage due to an impact applied from the external part is distributed, the precision machine is stored in a corrugated fiberboard case, and a cushioning material made of styrene foam resin is disposed between the precision machine and the corrugated fiberboard case. Even when the impact is applied from the external part, the cushioning material made of styrene foam resin absorbs this impact, so that the impact is not directly transferred to the precision machine and therefore the precision machine is protected from the impact.
The cushioning material made of styrene foam resin has high shock absorbing ability, but a die for foam molding corresponding to the shape of each cushioning material must be prepared. The die therefore increases a molding cost. The cushioning material made of styrene foam resin is bulky. Additionally, when the cushioning material is abolished and burned out, the cushioning material may produce black smoke to make the environment worse or radiate high heat to damage a furnace.
A cushioning material made of a corrugated fiberboard is therefore conventionally suggested. A cylinder body is assembled with a corrugated fiberboard punched in a predetermined shape, and its joint is locked with a metallic wire. A feather core or a pad punched from the similar corrugated fiberboard is installed in this cylinder body assembled with the corrugated fiberboard, thereby assembling a cushioning material having a predetermined cushioning material effect.
Such conventional cushioning material made of a corrugated fiberboard requires a plurality of members punched from the corrugated fiberboard, and is formed in combination of them. The cushioning material therefore disadvantageously has a complex structure, must be manually assembled because of difficulty of automatic assembling, and hence requires higher processing cost. Since the joint of the outer cylindrical body is locked with a copper wire, this wire must be removed for recycling the cushioning material and the cushioning material is unsuitable for recycle.
Additionally, a cushioning material formed by folding a blank is conventionally known. However, the manufacturing method requires not only one step of folding the blank but also a plurality of steps of folding it from two or more directions, and thus the folding and assembling steps are complex. Therefore, the manufacturing device also must be more complex and larger.
It is an object of the present invention to provide a recyclable cushioning material for packaging which can be formed with one sheet of corrugated fiberboard without using a plurality of individual members, assembled only by the folding step at a single station, and easily and rapidly manufactured by a simple manufacturing step with a simple manufacturing device, and does not require metal or the like at all. It is another object of the present invention to provide a method and a device for manufacturing the cushioning material.